seatbacks

The seatback is the upright component of a seat that provides support for a person's back. It is attached to the seat base and often extends to the shoulders or higher, depending on design. Seatbacks influence comfort, posture, and visibility, and may incorporate features such as lumbar support or adjustability.

Materials and construction: Seatbacks typically include a supporting frame made of wood, metal, or molded plastic, with padding such as foam and a upholstery layer of fabric, leather, or vinyl. In office chairs the backrest may be articulated and adjustable for height, tilt, and lumbar support. Some backrests are fixed, others are sculpted to fit the natural curve of the spine.

Applications: In homes, chairs and sofas use backrests of various shapes. In automobiles, the seatback forms part of the seat unit and may integrate a headrest, reclining mechanism, and passenger safety features. In aircraft, seatbacks often include a tray table, in-flight display, seat pocket, and safety information; in theaters and stadiums they may be high-backed for acoustic comfort or low-backed to maximize sightlines.

Design considerations: Key goals include ergonomic support, durability, ease of cleaning, and safety. Standards may govern structural integrity and crash performance in vehicles and aircraft, while accessibility features may require easy-to-use mechanisms for people with limited mobility.

History and variation: Backrests have existed since early chairs in ancient civilizations and have evolved with upholstery and ergonomic research. Today, designs range from simple fixed backs to highly adjustable, contoured backrests used in office seating.